1. FIELD OF THE INVENTION
This invention relates to a method of manufacturing a conveyor belt and an apparatus for executing the method, and more particularly to the conveyor belt having a group of steel cords as the tensile member.
2. DESCRIPTION OF THE PRIOR ART
The conventional tensile member, a conveyor belt, is composed of plural layers of tension elements made from woven cloth of cotton, rayon or various synthetic fibers. Recently steel cords have been utilized as the tensile member for the high strength conveyor belt. In a case of utilizing several hundreds of steel cords as the tensile member, each steel cord is required to have applied equal tension and to be embedded laterally in the belt.
If these works are omitted, the resulting conveyor belt will not become straight under operating conditions, and the embedded steel cord lengths become different from each other, thus causing irregular elasticity in the cross sectional area of the belt until it weaves, deforms and breaks down.
The known method of manufacturing a conveyor belt comprises passing a plurality of mutually parallel tensioned steel cords on a single or plurality of magnetic plates, applying a magnetic absorbing force to the steel cords thereby to cause a breaking force to the tension, and covering the rubber layers on and under the tensioned cords.
This method, however, cannot apply uniform tension on the whole steel cords because the magnetic plates do not produce equal absorbing force for the entire surface.
Therefore, an object of this invention is to provide a method and an apparatus for manufacturing a conveyor belt including the tensile member of the steel cords characterized by tensioning the steel cords with an electromagnetic roll assembly to impart a uniform and constant tension to each of the steel cords.